[U-Boot] [PATCH 1/2] mmc: add bcm2835 driver

[Stephen Warren]

On 11/04/2012 08:32 AM, Albert ARIBAUD wrote:
> Hi Stephen,
> 
> On Sun, 28 Oct 2012 22:36:25 +0530, Vikram Narayanan
> <vikram186 at gmail.com> wrote:
> 
>> On 10/28/2012 8:58 AM, Stephen Warren wrote:
>>> On 10/26/2012 05:33 AM, Vikram Narayanan wrote:
>>>> Some nitpicks.
>>>>
>>>> On 10/24/2012 10:20 AM, Stephen Warren wrote:
>> <snip>
>>>>> +static u8 bcm2835_sdhci_readb(struct sdhci_host *host, int reg)
>>>>> +{
>>>>> +    u32 val = bcm2835_sdhci_raw_readl(host, (reg&   ~3));
>>>>> +    val = val>>   (reg<<   3&   0x18)&   0xff;
>>>>> +
>>>>> +    return (u8)val;
>>>>> +}
>>>>
>>>> Can the above used magics be made as macros?
>>>
>>> This code was taken directly from the downstream Linux kernel, so I
>>> changed it as little as possible, to make comparisons easier. Still, if
>>> people want I can certainly make it easier to understand the expression
>>> a bit.
>>
>> Seems reasonable.
>>
>>> I don't think the issue is the magic numbers so much as understanding
>>> what the expression does; the magic are obvious then. It's simply
>>> extracting byte n from from a u32. Would the following be more obvious:
>>>
>>> byte_num = reg&  3;
>>> byte_shift = bytenum * 8;
>>> byte = (val>>  byte_shift)&  0xff;
>>>
>>> ... and similar for the other functions?
>>
>> This looks better to me than the former. Thanks.
> 
> Stephen,
> 
> Does this mean there'll be a new version of this patch?
> 
> Amicalement,

Hopefully. I'm waiting on Signed-off-by lines from Oleksandr Tymoshenko
and Dom Cobley (assuming they can provide them...) before I make this
change and repost.